ST. LOUIS — A month ago, the San Francisco 49ers became the first team to clinch its division, shutting out the St. Louis Rams to win the NFC West. Beat them again in the finale, and there’s a nice bonus for the Niners: the No. 2 seed in the NFC and a first-round bye.

Sure, they’re in. There’s still plenty of incentive for a franchise that’s made a rapid rise to the top under rookie head coach Jim Harbaugh.

“Anytime you could lock up a bye, you’d take it,” quarterback Alex Smith said. “Great opportunity for us, we’ve just got to go seize it.”

They couldn’t have picked a more vulnerable opponent.

The bedraggled Rams (2-13) are in danger of a dubious honor — landing the No. 1 pick in the draft for the second time in three years. All it’ll take is dropping their seventh in a row and the Colts winning at Jacksonville and again they will be at the bottom of the barrel.

St. Louis, just 10-37 under third-year coach Steve Spagnuolo and 12-51 with fourth-year general manager Billy Devaney, could be on the verge of a housecleaning. That’s led to a lot of questions this week about trying to save Spags’ job.

“We don’t worry about things we can’t control,” middle linebacker James Laurinaitis said. “He’s that way, we’re that way. We’re just going to go out there and play our rear ends off.”

Owner Stan Kroenke has been silent on the subject of what comes next for the Rams, who had been viewed as a franchise on the rise after last year’s six-win improvement.

Now they’re playing to a half-full stadium and reduced to muttering about injuries that have decimated the secondary and offensive line besides a persistent high left ankle sprain that almost assuredly will knock out quarterback Sam Bradford for a sixth game.

Attendance is likely to be more sparse than usual given the noon CST start coming off New Year’s Eve partying. The Rams asked Thursday for a 24-hour extension to meet NFL sellout requirements.

The 49ers (12-3) have already doubled their win total from a disappointing 2010 season, and even with a loss can get the No. 2 seed and bye if the Saints lose at home against the Panthers. If they can repeat the performance from the 26-0 whipping they handed out in San Francisco, Harbaugh would be just the fourth coach in NFL history to win 13 games in his first year. Two 49ers coaches have already done it, George Seifert going 14-2 in 1989 and Steve Mariucci at 13-3 in 1997.

San Francisco could also land its first 13-win season since ’97. A sixth road win would match their total from the previous three seasons, rewarding them for attention to detail.

“The biggest thing that I’d point to is a lot of little reasons that a lot of people think are the minutia that aren’t important that add up to make all the difference,” Harbaugh said. “And our guys continually do the little things, and they stack on each other and they build on each other. And lo and behold, you win games in high pressure situations, or find ways to do enough things right to win games and get better.

“Enough of those things lead to championships.”

The 49ers are stout on defense, on pace for a franchise record while allowing a league-low 13.5 points per game, and sound on offense behind come-back quarterback Alex Smith. They lead the NFL with a plus-26 turnover ratio, with the most takeaways (36) and the fewest turnovers (10) in the league.

Aldon Smith has 14 sacks, one shy of the NFL rookie record. Cornerback Carlos Rogers and free safety Dashon Goldson, two of the 49ers’ four Pro Bowl starters on defense, have six interceptions apiece.

Kicker David Akers, who has set an NFL record with 42 field goals, and punter Andy Lee are both Pro Bowlers, too.

They’ve stayed healthy, too, with 30 players appearing in every game and 12 making every start. That dwarfs the Rams’ totals of 14 and four. The 49ers have eight Pro Bowl representatives, the Rams none.

“They’ve put it together and you get on a roll,” Spagnuolo said. “It works both ways. You get on a roll winning, confidence and boom, boom, things are working and clicking.

“It happens the other way, too, where you can’t really find any continuity.”

The 49ers have won six of seven in a series knotted at 61-61-2, and Frank Gore always seems to get some of his best days against the Rams, totaling 832 yards and 11 touchdowns in 10 games. He’ll be facing a defense in danger of setting a franchise record for rushing yards allowed in a season.

The Rams have been giving up an NFL-worst 154.5 yards per game and if they surrender 159 yards it’ll break the previous franchise worst in 2008.

The 49ers got 144 yards the first time around.

The 49ers’ biggest worry might be encountering an opponent trying anything and everything to finish with a good taste.

“They have nothing to lose, so they can come out with whatever,” linebacker Patrick Willis said. “For us, there’s a lot riding on this game. We have to come out and play like we have all season. We know what’s at stake.”

Most every week, the Rams stay in it for a while and then a key play or two goes the wrong way and it snowballs to the finish of another failure. That was the case in the first meeting when the 49ers were held to three field goals in the first half, then busted loose with a pair of big plays — pass plays of 52 and 56 yards to Michael Crabtree and Kyle Williams.

Special teams have sprung several leaks in recent weeks, and the offense is the NFL’s worst, averaging just 11 points with 15 touchdowns in 15 games. They’re coming off a 27-0 loss at Pittsburgh, the second time they’ve been shut out the last month.

It’s been a complete bust of a comeback season for new offensive coordinator Josh McDaniels.

“No regrets, no regrets,” McDaniels said. “Every year is different, every year is a challenge in this league. You have to do everything you can to try to help the team win.”

More slogging lies ahead. The Rams totaled just 157 yards and were just 3 for 13 on third down in the first meeting against San Francisco.

Steven Jackson became the seventh player in NFL history to rush for 1,000 yards in seven straight seasons last week. Against the 49ers, he got just 19 yards on 10 carries.

“It was what we expected and they gave us exactly that,” Jackson said. “We’re going to have another tough time on Sunday but as long as you keep them balanced, and keep them out of what they want to do, we’ll be fine.”

Journeyman Kellen Clemens is expected to get his third straight start at quarterback. He passed for 91 yards last week in a 27-0 loss to the Steelers after throwing for 229 yards and a touchdown the previous week in a 20-13 loss to Cincinnati.

“If there’s a defense that’s better than Pittsburgh,” Clemens said, “we’re playing them this week.”

Despite San Francisco’s impressive 12-3 record, the 49ers’ offense leads the league in only one category — protecting the football.

San Francisco hasn’t committed a turnover in its last four games and leads the league in fewest giveaways with 10. If the 49ers don’t commit a turnover in Sunday’s season finale at St. Louis, they will tie the NFL record for fewest turnovers in a season, set last year by New England.

The 49ers also lead the league with 36 takeaways, making their plus-26 turnover differential the NFL’s best. San Francisco ranks just 26th in the league in total offense, but that unit has contributed to the team’s successful formula by limiting mistakes and holding onto the ball.

The 49ers had a minus-1 turnover differential last season, when they committed 23 turnovers. The team’s skill players on offense are essentially the same as last year, but the big change has come in the methodology of first-year coach Jim Harbaugh and his staff that has transformed San Francisco into a contender after eight seasons without a winning record or playoff berth.

“There are other things that go into it other than, ‘Hey, guys, let’s just take care of the ball today,’” Harbaugh said Friday after his team’s final practice of the regular season. “There is scheme, there’s philosophy that goes in there. It’s the pride that the players have in protecting the football, understanding situational football.”

Harbaugh said the 49ers have emphasized that scheme since the team’s first practice in July, and it certainly has showed in the results. San Francisco has not committed a turnover in its past 18 quarters since quarterback Alex Smith threw an end-zone interception in the final seconds before halftime of a Thanksgiving Day loss at Baltimore.

Smith has been the catalyst behind San Francisco’s low turnover rate. The seventh-year pro from Utah has thrown 415 passes this season but only five have been intercepted, the fewest of any starting quarterback in the league.

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Around the league

Dolphins • Running back Reggie Bush, a 1,000-yard rusher this year for the first time in his six-year career, will miss Sunday’s season finale against the Jets with a knee injury he suffered last week against New England.

Raiders • Receiver Jacoby Ford made it through a third straight practice without any setbacks and expects to play in Oakland’s regular-season finale against San Diego. Ford hasn’t played since injuring his left foot during Oakland’s win in San Diego on Nov. 10.

Packers • Green Bay will be without three key players on offense against Detroit. Running back James Starks (knee/ankle), receiver/kick returner Randall Cobb (groin) and receiver Greg Jennings (knee), who has missed the last two games, won’t play in the regular-season finale. Coach Mike McCarthy would not say Friday whether quarterback Aaron Rodgers will sit out.

Patriots • Tom Brady is listed as “probable” on New England’s injury report for its regular-season finale against Buffalo. An injury to his left, non-throwing shoulder limited Brady’s participation in practice Friday for a second straight day after he sat out practice on Wednesday.

The 49ers’ persona has been identified, at least in terms of how they have forced a league-high 35 turnovers.

They have patterned themselves after the honey badger, dubbed nature’s most fearless animal by the Guinness Book of World Records.

The 49ers recently saw a viral video of the honey badger at work. A beehive was invaded for its larvae. A cobra snake was consumed, regardless of venom. Holes were trenched to nab mice.

“Honey badger don’t care. … It just takes what it wants,” said a narrator in the video that’s generated nearly 28 million views on YouTube this year.

A couple weeks ago, the 49ers (11-3) spliced highlights from this NFC West-winning season into the honey badger video, making for a rousing film session at a team meeting.

That explains why coach Jim Harbaugh referred to the honey badger in his locker room address after Monday night’s 20-3 win over the Pittsburgh Steelers, a victory overshadowed by two power outages at Candlestick Park.

“Honey badger don’t care about no lights,” Harbaugh said, as captured by video on the 49ers website.

This “honey badger” business isn’t new to sports. It became the nickname of LSU cornerback Tyrann Mathieu en route to his fifth-place finish in this year’s Heisman Trophy voting.

After Harbaugh’s honey badger drop, he resumed his locker-room speech with the 49ers’ more renown catchphrase: “Let me ask you a question, who could possibly have it any better than

us?” A team-wide chorus responded: “Nobody!”

And nobody has a better turnover differential than the 49ers at plus-25 (10 turnovers, 35 takeaways). Their closest competitor is the team they’re chasing for the NFC’s No. 1 playoff seed, the Green Bay Packers, who have a plus-20 margin (12 turnovers, 32 takeaways).

Although the 49ers have forced the league’s most turnovers, their host Saturday, the Seattle Seahawks, have tallied a league-high 18 since Week 10. The 49ers have the second-most, with 16 turnovers in that six-game span.

On Tuesday in the 49ers’ locker room, footballs sat in the lockers of cornerback Tarell Brown and safety Dashon Goldson, footballs they intercepted against the Steelers. Carlos Rogers recorded the first of Monday night’s three interceptions, but he threw that ball into the crowd.

Rogers has a team-high six interceptions this season, and he hasn’t kept any of those footballs as mementos. He instead prefers a team-issued game ball that Harbaugh distributes as weekly rewards.

In a season bursting with run-defense records, the 49ers aren’t near a record pace for forcing turnovers. Their respectable tally of 35 takeaways is far off the standards set by the 1961 San Diego Chargers (66), 1984 Seahawks (63) and 1983 Washington Redskins (61).

The 49ers’ 21 interceptions are their most since 2003, when they tallied 23. The franchise record is 39 interceptions in 1986. Although they have recovered a league-high 14 fumbles by their opponents, the 49ers’ record is 27, in 1978.

It’s safe to say these 49ers won’t be duplicating the efforts of the franchise’s first Super Bowl team, a 1981 squad that forced 48 turnovers (27 interceptions, 21 fumble recoveries). Nor will these 49ers match the 1983 Redskins’ plus-43 turnover differential.

But defensive backs have stayed after practice to catch balls thrown by quarterbacks and a machine. Linebackers have done turnover drills before practice. The results are showing.

“It’s remarkable,” Rogers said of the turnover tally. “I just saw that we lead the league. It’s a credit to the players and the coaches who’ve put us in the right situations.

“And we’re hanging on to the ball.”

So is the 49ers’ offense. That unit’s persona: ball hog. The 49ers have committed only 10 turnovers, including Alex Smith’s five interceptions and two lost fumbles. Harbaugh said Smith has been “uncanny in the pocket” in holding on to the ball despite being sacked a league-high 39 times.

But the honey badger probably doesn’t care about all that.

For more on the 49ers, see Cam Inman’s Hot Read blog at blogs.mercurynews.com/49ers.